Abstract:
Determination of the source and fate of natural (higher plant lipids, marine
lipids, etc.) and anthropogenically (e.g., petroleum, coal emissions) derived
hydrocarbons and oxygenated compounds in the environment was accomplished
using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS)
to characterize or identify molecular biomarkers to be utilized as tracers. The
distributions and abundances of biomarkers such as straight chain homologous series
(e.g., n-alkanes, n-alkanoic acids, n-alkan-2-ones, n-alkanols, etc.) and cyclic
terpenoid compounds (e.g., sesquiterpenoids, diterpenoids, steroids, triterpenoids)
were identified in epicuticular waxes from conifers of western North America
(natural emissions). These biomarkers and their thermal alteration derivatives were
also identified in smoke emissions from known vegetation sources (e.g., conifers,
deciduous trees and grasses) and were then applied as tracers in soils, soils that
contained wildfire residues and soil/river mud washout after wildfire burning. Where
possible, the reaction pathways of transformation from the parent precursor
compounds to intermediate and final alteration products were determined from GC-MS
data. In addition, molecular tracer analysis was applied to air, water and
sediment samples collected from a lacustrine setting (Crater Lake, OR) in order to
determine the identities, levels and fates of anthropogenic (i.e., petroleum
hydrocarbon contamination from boating and related activities) hydrocarbons in a
pristine organic matter sink. This work demonstrated that biomarker tracer analysis is
a useful tool for developing environmental management and pollution mitigation
strategies.
